This project has several specific goals aimed at increasing our understanding of the vertebrate retina and its interdependence on the retinal pigment epithelium. These studies will contribute to our knowledge of retinal organization and to our understanding of the responses of the retina to injury. The effect of increased light intensity on cyclic cone disc shedding will be studied in ground squirrels. Synaptic organization and circuitry of the human retina will be studied in serial sections by electron microscopy, and the morphology of human retinal neurons studied by Golgi impregnation techniques. We will use light and electron microscope autoradiography to determine the patterns of uptake of various molecules (uridine, proline, galactose, dopamine, Gamma-aminobutyric acid, muscimol, taurine) by the normal cat retina and retina injured by separation of neural retina and pigment epithelium. Changes in the uptake of these molecules with time after injury will be monitored to determine if we can find metabolic changes that parallel the morphological changes described by us and others. The distribution of cytoskeletal proteins (tubulin, microtubule-associated proteins, actin, neurofilaments, vimentin, glial fibrillary acidic protein) and surface saccharides will be studied in normal retina and isolated retinal cells by cytochemical studies using antibodies and lectins. Changes in the distribution of cytoskeletal proteins will also be studied after separation of neural retina and pigment epithelium and correlated with previously described morphological changes. We will use indirect fluorescence to detect lectin binding, indirect immunofluorescence, peroxidase-anti-peroxidase, protein A-gold, or immunogold techniques will be used to study antibody binding. Protein A-gold or immunogold techniques will be used to study antibody binding by electron microscopy. Monoclonal antibodies will be raised against cat retina and pigment epithelium and the localization of their specific antigens detemined immunocytochemically by light and electron microscopy. One of the most important long-term goals of this project is to use information obtained from these experiments to rescue retinal cells after retinal injury.